Effect of 3-tesla magnetic resonance imaging on various pressure programmable shunt valves.

OBJECT This study investigated the changes in the valve pressure setting of several magnetic pressure-programmable valves after exposure to a 3-tesla magnetic field. METHODS Five each of four types of pressure-programmable shunt valves were tested: Sophy Polaris, Sophy SM8, Codman-Hakim, and Medtronic Strata. First, the valves were advanced toward the 3-tesla static magnetic field. Second, T1-, T2-, and diffusion-weighted magnetic resonance (MR) images were generated with a radiofrequency magnetic field. Any changes in the pressure setting were observed by visual inspection with a compass or radiography. The pressure settings were changed after exposure to the static magnetic field in all programmable valves except for the Sophy Polaris. All pressure settings studied were unchanged after exposure to both static and radiofrequency magnetic fields (T1-, T2-, and diffusion-weighted MR imaging) in the Sophy Polaris. CONCLUSIONS The Sophy Polaris valve allows shunt-dependent patients who need a programmable valve to undergo 3-tesla MR imaging.

[1]  M. Sindou,et al.  Transcutaneous pressure adjustable valve for the treatment of hydrocephalus and arachnoid cysts in adults , 1993, Acta Neurochirurgica.

[2]  T. Czech,et al.  Clinical experience with a new pressure-adjustable shunt valve , 2005, Acta Neurochirurgica.

[3]  S. Kashiwagi,et al.  Intracranial pressure monitoring using a programmable pressure valve and a telemetric intracranial pressure sensor in a case of slit ventricle syndrome after multiple shunt revisions , 1991, Child's Nervous System.

[4]  C. Lumenta,et al.  Clinical experience with a pressure-adjustable valve SOPHY in the management of hydrocephalus , 1990, Child's Nervous System.

[5]  G. Dooms,et al.  Safety of the adjustable pressure ventricular valve in magnetic resonance imaging: problems and solutions , 2004, Neuroradiology.

[6]  K. Miwa,et al.  Pressure changes observed in Codman-Medos programmable valves following magnetic exposure and filliping , 2001, Child's Nervous System.

[7]  S. Felber,et al.  Transcutaneous pressure-adjustable valves and magnetic resonance imaging: an ex vivo examination of the Codman-Medos programmable valve and the Sophy adjustable pressure valve. , 1997, Neurosurgery.

[8]  P. Black,et al.  The use of the Codman-Medos Programmable Hakim valve in the management of patients with hydrocephalus: illustrative cases. , 1994, Neurosurgery.

[9]  R. Battersby,et al.  Do we need variable pressure shunts? , 1992, British journal of neurosurgery.

[10]  A. Chutorian,et al.  Increased intraventricular pressure without ventriculomegaly in children with shunts: "normal volume" hydrocephalus. , 1979, Neurosurgery.